Major Category
Physical/Radiation
Description
A naturally occurring isotope that comprises about 0.012% of total potassium; K-39 (93% of potassium) and K-39 (7% of potassium) are not radioactive. Elemental potassium is a soft, silver-white metal. [Argonne]
Sources/Uses
Common element in the soil, the ocean, and in plants and animals; Present in the minerals carnallite, feldspar, saltpeter, greensand, and sylvite; [Argonne]
Comments
Source: Naturally occurring;
Half-Life: 1.3 billion years;
Specific Activity: 0.0000071 Ci/g
Decay Mode: Beta, Electron Capture;
GI Absorption: "Almost completely absorbed"
Lung Clearance Half-Time: Days
Internal Toxicity: High
Annual Limit on Intake: 0.3 mCi
Tenth-Value Layer: 38.7 mm Pb
Gamma Ray Constant: 0.7 R/h @ 1 cm per mCi
Radiation Energy (MeV): Beta 1.31 (89%); Gamma 1.46 (11%);
[See Glossary for references.] See "Radiation, ionizing."
Half Life
30 days; [Argonne]
Other Information
No other related information on this agent was found.